Improved method of manufacturing a thin walled receptacle



May 16, 1933. R. SERENYI IMPROVED METHOD OF MANUFACTURING A THIN WALLED RECEPTACLE Filed Sept. 5, 1930 Patented May 16, 1933 UNITED STATES RICHARD SERENYI, OF ZURICH, SWITZERLAND IMPROVED METHOD OF MANUFACTURING A THIN WALLED RECEPTACLE Application filed September 5, 1980, Serial No, 479,982, and in Switzerland February 8, 1930.

This invention relates to an improved method of making at seamless thin walled container of acetyl cellulose or similar material for example a collapsible tube, which is transparent at least in part, and also to a method of manufacturing the same.

According to the invention an acetyl cellulose solution is applied in a thin layer to a former or core the shape of which substantially conformswith the desired shape of the tube or container to be manufactured, for example by dipping the former into an acetyl cellulose solution, or by spraying or pouring the acetyl cellulose solution over the former.

By this means a skin is formed on the former or core when the solvent for the acetyl cellulose evaporates and the said skin is peeled ofl the former by turning the skin inside out, i. e. the free edge of the skin is drawn over the remaining portion of the skin. The former or core can if desired be provided with surface configurations such as depressions which then-appear on the finished container. I

For carrying the method into practical efiI'ect there is advantageously provided a ring loosely arranged on the former, the free edge of the skin adhering to this ring and the said ring. serving to facilitate the drawing of the free edge over the remaining portion of the skin and thereby to allow the skin to be completely removed from the former. By this means the skin is readily removed from the former without the formation of tears or folds. T he said skin can be further treated in known manner as by forming or pressing it into the desired shape. By means of the method according to the invention seamless thin-walled tubes (wall thickness 0.4 mm or less) for example airtight closed tubes or containers, can be manufactured.

A constructional example of a device in accordance with the invention is illustrated diagrammatically in the acompanying drawing, with regard to which an example of a manner of carrying the method of the invention into effect is described, and in which Figure 1 is a vertical section of the container with the form and ring in elevation, Figure 2 is an elevation of the ring with the form in lowered position indicated diagrammatically in dotted lines and the film of cellulose also indicated in dotted lines, and Figure 3 is partly an elevation and partly a section of a completed receptacle as constructed in accordance with my improved process.

In a container 1 is a solution of acetyl cellulose 2. For making a seamless thinwalled collapsible tube container a cylindri cal former or core 3 is dipped into the solution. Loosely arranged on the former 3, which is broadened in conical manner at 4 is a ring 5. When the former 3 is dipped into the solution the ring 5 is applied against the conical portion 4 and the ring and former are dipped into the solution to such an extent that the lower end of the ring 5 becomes wetted by the solution. The former 3 with the ring 5 is then removed from the solution. By evaporation of the solvent there is formed on the former a very thin skin of acetyl cellulose, the thickness of which may amount to from 0,04 to 0,4 mm. The thickness of the skin is dependent upon the viscosity of the solution. Now the ring 5 is moved away from the conical portion 4 towards the free end of the former 3. The skin formed on the surface of the former 3 is thereby turned inside out and drawn off, as is shown in dotted lines in Fig. Drawing otl of the skin is cii'ectcd without forming cracks or permanent folds and the skin retains the outer configuration of the former 3. The container thus formed is subsequently removed from the ring A closure 0 (Fig. 3) known per se is attached in known manner to the neck of the container, said closure consisting of a fixture firmly attached to tube 7 and made of hard material such as celluloid or like material. The fixture comprises a screw threaded cap adapted to be screwed on a screw-threaded socket. The reduced portion of tube 7 projects over the face of said socket in such a manner that it may be cut-olf to open the container. The open end of the tube 7 is closed, after filling, as by folding or dipping in a cement or by applying acetyl cellulose or the like which hardens. I

The former 3 may be provided with surface projections or depressions. The acetyl cellulose conforms to the configuration of these projections or depressions so that these are reproduced on the finished container in the manner of a stamped out relief. If desired lettering or drawings may be appliec to the container in this way.

In order to ensure that when the container is turned inside out the parts of the skin which slip over each other will not stick together the outer surface is advantageously coated with soap solution or other suitable material.

Instead of collapsible tubes other thin- ,walled vessels or containers, which may be conical instead of cylindrical, may be manufactured in seamless and foldless manner. The containers can if desired be subsequently altered in shape in manner known per se as by being pressed out. Preferably the material used for manufacturing the collapsible tubes is as transparent as possible. The acetyl Cellulose solution may be applied to the former by spraying, pouring, etc. instead of by dipping.

In place of acetyl cellulose solution any other similar material might be used.

The device for carryin the method into efiect ma be so arrange that for turning or reverslng the skin the ring 5 or a corresponding element is fixed and the former or core is moved.

Only one former and ring is shown but it vis understood that any number thereof might be arranged in a common frame or on the circumference of a rotary drum or ring and a plurality of casings might be produced simultaneously or in a continuous manner.

What I wish to claim and secure by the U. S. Letters Patent, is

The process of manufacturing a thin walled receptacle consisting in providing a form with a lateral broadening projection extending therearound at a point spaced from oratin the solvent to form a skin adhering to the form, the exposed portion of the broadening projection thereof and the lower portion of the ring and movin the ring to the skin covered end of the orm to thereby double the skin or wall at the end thereof adherent to the ring and to strip the skin or wall from the form and turn the same inside out while so stripping the same.

In testimony whereof I affix my signature.

RICHARD SERENYI.

one end, placing a ring around the form so that one end of the ring bears around the point of greatest diameter of said projection, covering the exterior of the lower portion of said ring, the exposed portion of the broadening projection of the form and said form from said broadening projection to said end thereof with a film of cellulose solution, evap- 

